In the present specification, an organic electronic device is an electronic device using an organic semiconductor material, and requires exchanging of holes and/or electrons between electrodes and organic semiconductor materials. The organic electronic device may be largely divided into the following two categories according to an operation principle. First, there is an electronic device in which an exiton is formed in an organic material layer by a photon that flows from an external light source to the device, the exiton is separated into electrons and holes, and the electrons and the holes are transferred to the other electrodes, respectively and used as a current source (voltage source). Second, there is an electronic device in which holes and/or electrons are injected into organic semiconductor material layers forming an interface with the electrode by applying a voltage or current to two or more electrodes, and the device is operated by the injected electrons and holes.
As examples of the organic electronic device, there are an organic light emitting device, an organic solar cell, an organic photoconductor (OPC) drum, an organic transistor and the like, and an electron/hole injection material, an electron/hole extraction material, an electron/hole transporting material or a light emitting material is required in order to drive all these devices. Hereinafter, an organic light emitting device will be mainly described in detail. However, in the organic electronic devices, all of the electron/hole injection material, the electron/hole extraction material, the electron/hole transporting material and the light emitting material are operated based on a similar principle.
In general, an organic light emitting phenomenon refers to a phenomenon that converts electric energy into light energy by using an organic material. The organic light emitting device using the organic light emitting phenomenon has a structure which typically comprises an anode, a cathode, and an organic material layer that is disposed therebetween. Herein, organic material layers frequently have a multilayer structure that comprises different materials in order to enhance efficiency and stability of the organic light emitting device, and for example, and may comprise a hole injection layer, a hole transporting layer, a light emitting layer, an electron transporting layer, an electron injection layer and the like. In the structure of the organic light emitting device, if a voltage is applied between two electrodes, holes are injected from an anode into the organic material layer and electrons are injected from a cathode into the organic material layer, and when the injected holes and the electrons meet each other, an exciton is formed, and light is emitted when the exciton falls to a bottom state. It is known that this organic light emitting device has properties such as self light emission, high brightness, high efficiency, low driving voltage, a wide viewing angle, high contrast, high speed response and the like.
In the organic light emitting device, the material that is used as the organic material layer may be classified into a light emitting material and an electric charge transporting material, for example, a hole injection material, a hole transporting material, an electron transporting material, an electron injection material and the like according to a function thereof. Examples of the light emitting material include blue, green, and red light emitting materials and yellow and orange light emitting materials required for realizing better natural colors according to the emission color. In addition, in order to increase color purity and increase light emission efficiency through energy transfer, a host/dopant system may be used as the light emitting material. In the principle, by mixing a dopant that has a energy bandwidth gap that is lower than that of a host mainly constituting the light emitting layer and has excellent light emission efficiency with a light emitting layer in a small amount, an exciton that is generated in the host is transported to the dopant to produce light having high efficiency. At this time, since the wavelength of the host moves to the wavelength bandwidth of the dopant, light at a desired wavelength may be obtained according to the kind of dopant used.
In order to sufficiently show excellent properties of the above-described organic light emitting device, a material constituting the organic material layer in the device, for example, a hole injection material, a hole transporting material, a light emitting material, an electron transporting material, the electron injection material and the like need to be mainly supported by stable and efficient materials, but the development of a stable and efficient organic material layer material for organic light emitting device has not been sufficiently achieved. Accordingly, there is a continuous need for developing a new material.